Two groups of children aged between 4 and 12 years were studied to look at the effect of stress, time and type of questioning on memory. One group comprised 17 children having a blood sample taken as part of their medical care. The other group of 24 children were studied after reacting with a friendly stranger at their school. Memory was tested either four to ten days after the event or after three to six weeks. Memory was assessed by free recall, by questioning with cues, by structured questions, by leading or misleading questions and by asking the children to identify the blood-collection technician or friendly stranger from a photographic line-up. There was no difference between memory for the stressful or nonstressful events. The older children performed better in free recall although what the younger children did recall was highly accurate. The use of cues facilitated recall in all age groups. Children aged four to six years were less accurate than those aged seven to 12 years when objective questioning was used. Errors were more likely to be errors of omission than of commission in all age groups. Memory was less accurate after the longer time interval. With increasing interest in the reliability of children as witnesses, methods need to be found which will enable the child witness to give the maximum amount of accurate information. Those likely to be working with the child witness need to develop skills in talking with young children.